Six Sigma Work Methodology

This methodology can be divided into 5 steps:

DEFINE

• What is the problem?

• What does the customer expect?

Define the problem / select the project. Describe the effect caused by an adverse situation, or the improvement project that you want to carry out, in order to understand the current situation and define objectives. Select the team, preferably a cross-functional team, with a clearly and fully defined objective.

TO SIZE

• Can I measure it?

• How is my process performing?

Define and describe the process. Define the elements of the process, its steps, inputs, outputs and characteristics.

Evaluate measurement systems. Evaluate the capacity and stability of measurement systems through repeatability, reproducibility, linearity, accuracy and stability studies.

ANALYZE

• What is my current process?

• What are the root causes?

Determine the significant variables. The process variables defined in point 2 must be confirmed by means of experiments and / or multivariate studies, to measure the contribution of these factors in the variation of process. Hypothesis tests and confidence intervals are also useful in process analysis.

Evaluate the stability and capacity of the process. Determine the ability of the process to produce within specification through long and short capacity studies, while evaluating the defective fraction.

TO GET BETTER

• How can I fix those root causes?

Optimize and strengthen the process. If the process is not capable, it must be optimized to reduce its variation. It is recommended to use design of experiments, regression analysis and response surfaces.

Validate the improvement. Conduct capacity studies.

CONTROL

• How can I keep those root causes in check so that I don't have to fix them again?

Control and monitor the process. Monitor and maintain control of the process. Continuously improve. Once the process is capable, better operating conditions, materials, procedures, etc., that lead to better process performance, should be sought.